Older Robust Physique Vibrant Green Tank

Create an image featuring an older man with a robust physique, wearing a vibrant green tank top with a solid color instead of stripes. He should have a full white beard and be wearing round, retro sunglasses. The background should be a simple, light gray to ensure the focus remains on him. Have him flexing his arms and smiling confidently, exuding a sense of fun and vitality.